Chapter 9 Q & A Flashcards
what is the best extimate of the diameter or width of the sound beam as it exits the transducer
A 6 mm
B 9 mm
C 12 mm
D 8 mm
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C
beam diameter at beginning is same as active element
what is the diameter of the sound beam at a depth of 8 cm
A 6 mm
B 9 mm
C 12 mm
D 8 mm
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A
at end of near zone, beam diameter is one half width of the transducer diameter
what is the diameter of the sound beam at a depth of 16 cm
A 6 mm
B 9 mm
C 12 mm
D 8 mm
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C
depth equal to 2 near zone lengths the beam diamter is same as the diameter of the active element
at what depth is the focus
A 6 cm
B 8 cm
C 1 cm
D 12 mm
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B
focal depth is the same as the length of the near zone
what depth marks the beginning of the focal zone
A 6 cm
B 8 cm
C 12 mm
D 8 mm
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A
focal zone is the region around the focus./ in this example the focal zone begins at a depth of 2 cm shallower than the focus
what depth marks the end of the focal zone
A 6 cm
B 8 cm
C 10 mm
D 10 cm
E 8 mm
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D
the focal zone is the region around the focus. In this example the focal zone ends at a depth 2 cm deeper than the focus
at which of the following depths is the beam narrowing
A 6 cm
B 8 cm
C 12 cm
D 10 cm
E 12 cm
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A
the beam narrows within the near zone
the only dpeth within the near zone is choice A
at whioch of the following is the beam widening
A 2 cm
B 4 cm
C 6 cm
D 8 cm
E 9.375 cm
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E
the beam widens in the far zone.
the only depth within the far zone is choice E
at which of trhe following depths is the beam most likely to have the same diameter as it has at a depth of 11 cm
A 1 cm
B 3 cm
C 5 cm
D 8 cm
E 14 cm
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C
think of the beam as being symmetrical around the focus. Thus the beam diameter will be similar when it is 3 cm shallower and 3 cm deeper than the focus
which of the following terms does not belong
A focus
B end of the near zone
C end of the fraunhofer zone
D middle of the focal zone
C
the end of the Fraunhofer zone is the end of the sound beam
a pair of 6 MHZ probes are identical except for the active element diameter. The active element diameters are 6 mm and 10 mm respectively. The sound beam of which probe will have a shallower focus
6 mm
smaller diameter crystals prodcue shallower foci
a pair of 9 mm diamter probes are identical except for freq. which is 3 MHz and 6 MHz respectively. which will have a shallower focus?
3 MHz has a shallower focus,
focal depth increases with freq
which of the following probes creates a beam with the depest focus
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 6 mm dia, 2 MHz
D 5 mm dia, 8 MHz
B
longer focal lengths are associated with larger diameter and higher freq
which of the following probes creates a beam with the shallowest focus
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 4 mm dia, 2 MHz
D 5 mm dia, 8 MHz
C
shorter focal lengths are associated with smaller diameter and lower freq
which of the folloing probres creates a beam with teh shallowest focus
A small dia, high freq
B large dia, high freq
C small dia, low freq
large dia, low freq
C
shorter focal lengths are associated with small diameter and low freq
active element diameter and near zone length are directly related
true/false
true
transducer freq and near zone length are inversely related
true/false
false
wavelength and near zone length are inversely related
true/false
true
a pair of 6 MHz probes are identical except for the active element diameters, which are 6 mm and 10 mm respectively. Which beam will be more compact in the far filed?
10 mm probe has less divergence
a pari of 9 mm diamter probes are identical except for freq, which are 3 MHz and 6 MHZ
which sound beam will spread out more in the far field
the 3 MHZ beam is more divergent
which of the following probes creates a beam with the least divergence
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 6 mm dia, 2 MHz
D 5 mm dia, 8 MHz
b
divergence is minimized with large diameter high freq probes
which of the followoing probes creates a beam with the most divergence
A 4 mm dia, 4 MHz
B 6 mm dia, 8 MHz
C 6 mm dia, 2 MHz
D 5 mm dia, 8 MHz
C
divergence is pronounced with small diameter low freq probes
which of the folloing probes creates a beam with the most divergence
A small dia, high freq
B large dia, high freq
C small dia, low freq
D large dia, low freq
C
divergence is pronounced with small dia and low freq probes
transducer freq and beam divergence are inversely related
true/false
true
higher freq creates less divergent beams
active element dia and beam divergence are inversely related
true/false
True
crystals with larger dia create less divergence
the freq of a transducer does not change. If the diameter of the new piezoelectric crystal increases what happens to the near zone length
increases
freq of a transducer does not change. if the dia of the new piezoelectric crystal increases what happens to the beam diameter in the far zone
decreases
freq of a transducer does not change. if the dia of the new piezoelectric crystal increases what happens to the wavelength
no change
freq of a transducer does not change. if the dia of the new piezoelectric crystal increases what happens to the beam diameter in the near zone
increases
at what location is the sound beam diamter three times greater than the transducer diameter
A at the end of the near zone
B at a depth equal to four focal lenghts
C at the end of the far zone
D at the triple diameter depth
B
the only region where the beam diameter exceeds the transducer diameter is at depths exceeding two focal lengths
what is the shape of a sound beam created by a tiny piece of PZT
A hour glass
B V-shaped
C round
D shaped like a tube
B
small PZT creates a V-shaped beam
diffreaction pattern
Huygens wavelet
which of the following explains why a sound beam created by a disc shaped crystal is hourglass shaped?
A Bernoullis Principle
B SHeffilds Law
C Ohms law
D Huygens Principle
D
Huygens Principle
which of the following locatoins is the deepest
A end of the fresnal zone
C end of the focal zone
C end of the Fraunhofer zone
D end of the near zone
C
end of the Fraunhofer zone
which of teh folloing locations is the most shallow
A beginning of the far zone
B beginning of the focal zone
C focal depth
D beginning of the Fraunhaofer zone
B
of these choices the beginning of the focal zone is the most shallow